1. Field of the Invention
The present invention relates generally to a personal network, and more particularly to a method and device for authenticating a personal network entity in a personal network.
2. Description of the Related Art
With an exponential increase in use of Consumer Electronics (CE) devices in which short distance communication is enabled (e.g., an Motion Picture Experts' Group Audio-Layer 3 (MP3) player, a Portable Multimedia Player (PMP), a game machine, a netbook, etc.), users seek methods for conveniently downloading content to such devices.
A user may search for reproducible content in consumer electronics over the Internet by using a Personal Computer (PC) and then download the searched content. After downloading the content to the PC, when a consumer electronics device and the PC are connected to each other through a dedicated cable, the consumer electronics device can download the content from the PC. In another similar process, the cable may be replaced with a Bluetooth connection (i.e., a BLUETOOTH® specification-compliant connection), and the content can be shared between devices by using a Bluetooth scheme.
However, methods by which consumer electronics devices can directly access a long distance communication network are highly limited. For example, some of consumer electronics devices can access a long distance communication network only when accessing Internet through a Wireless-Fidelity (Wi-Fi) connection in an area where there is an Access Point (AP). Accordingly, there is a need for a method by which consumer electronics devices (which may have access to short distance communications without an ability to directly access a long distance communication network) may access a long distance communication network through a gateway to download content. According to this need, a CPNS (Converged Personal Network Service) is proposed.
The CPNS refers to a service for providing a corresponding service or a content after one Personal Network (hereinafter, referred to as a “PN”) configured by a combination of a device, which acts as a gateway in charge of communication with a long distance communication network, and a consumer electronics device, which reproduce an actual service and content, is constructed such that the consumer electronics device accesses a service/content providing server located in the long distance communication network through the device acting as the gateway. In such a CPNS, the device acting as the gateway is referred to as a Personal Network (PN) gateway and the consumer electronics device accessing the long distance communication network through the PN gateway are referred to as a Personal Network Entity (PNE).
Meanwhile, in such a PN, an authentication protocol suitable for each PNE is required prior to providing a service to each PNE. The authentication protocol corresponds to a protocol performed to recognize communication entities and is implemented in advance in order to perform other communications via the protocol in the future.
A method for a general device authentication protocol is largely divided into a method of using a symmetric key and a method of using a public key. However, both of methods require a secure storage apparatus for their devices since the two methods perform an authentication after storing a key. In particular, in the public key method, authentication is performed after a private key of the device is stored, and in the symmetric key method, authentication is performed after a secret key of the device is stored. However, when there is no secure storage apparatus in the device, it is possible to copy secret information from a storage space of the device vulnerable to attacks in comparison with a server, so that the copied secret information may be used for a malicious authentication of the device.
However, the PNE device cannot directly communicate with the PN server, and the PNE device may also operate in various environments including devices such as a fax machine, a scanner, a printer, a TeleVision (TV), a set top box, an audio, a camera, an MP3 player, a PMP, a refrigerator, a washing machine, a microwave oven, etc. Accordingly, a conventional authentication method is not suitable for the PNE device, and all devices using such a system should implement secure storage spaces in order to protect against malicious authentication.